1. Field of the Invention:
This invention relates to a switching system for interconnecting any two terminals of a communication network and, more particularly, a switching system which uses an arrangement of data and address buses allowing the switching function to be performed in a simpler and more efficient manner.
2. Prior Art:
This invention can advantageously be used in those communication networks which consist of several sub-systems comprising each a number of transmitting/receiving devices, which may be, for example, telephone sets in the case of a telephone network, or computer terminals in the case of a data transmission network. Said devices transmit and receive information via time-division multiplexed links. Any suitable type of modulation, for example, pulse-code modulation (PCM), in which the complex waveform of the signal to be transmitted is sampled, quantized and coded in digital form, can be used to convey the information on such links, except where a communication system between a computer and its peripheral units is involved since, obviously, the original information would already be in digital form. The present invention permits achievement of full-duplex communication between two transmitting/receiving devices in two distinct sub-systems.
U.S. Pat. No. 3,632,883 describes a telecommunication exchange with time-division multiplex for conducting information received on a channel of a time-multiplexed communications trunk to a selected channel of a second time-multiplexed communications trunk. The information from all channels is sequentially stored in a cyclic storage register in fixed relationships with cyclic code numbers generated by a local clock generator. At a clock instant determined by the address of an output channel, the address of an input channel is serially introduced into a second cyclic register. The output of the second cyclic register is decoded and used to switch the output of the first cyclic register corresponding to the selected input channel to an output line.
However, one of the drawbacks of such an approach, as described in said patent, is that it does not permit achievement of a full-duplex link.